Gesellschaft



oun'r BETH, OFlBERLIN, v V Y 4 GESELLSCHAFT, or 331mm, c aimant.

Patented Oct. 21, 1930 UNITED TE IVMAKINQHYIDROXY comrounns oa m Y I it No Drawing. Application filed April 10, 1928, Serial No. 269,026, and in Germany Aprn 14,1927. r

This invention relates to a method for making hydroxy compounds of pyridine and consists in treating halopyridine or halopyridines having further non saponifiable substituents', with acid reacting saponifying agents such as aqueous hydrohalic acids especially aqueous hydrochloric acid.

The treatment of the starting material with the acid reacting saponifying agent is preferably carried out at raised temperatures upto about 350 C. The reaction may be carried through in presence or absence of organic solvents or diluting agents. Halopyridines, in which the halogen is in the 2-position are especially suitable as starting materials; they may have further non saponifiable substituents such as halogen, the hydroxy group, the amino group, the nitro group, the arsenic acid group, an alkyl or an aryl group, especially in the 3- or 5-position.

Examples 2. g. of 2-chloropyridine mixed with 220 com. of, concentrated hydrochloric acid are treated-in the same manner as in Example 1 the 2-chloro-5-nitropyridine. The yield of Q-hydroxypyridine is quantitative;

3. 73 g. of 2-5-dichloropyridine and, 200; 1'

com. of'concentrated hydrochloric acid are heated under pressure forabout five hoursto about 150 'C. The dark-brown reaction i product is diluted with 500 com. of water.

' ric [acid are A crystalline mass of faintly yellow2-hydroxy-5-chloropyridine,melting at 163 C.

. 7 4E. 20. of Q-chIOro-S QchlorO- 5rnitropyri r' dine and 100 com. of concentrated hydrochloboiled for two hoursin a vessel with reflux-condenser. The reaction product is diluted with water .andjsteam distilled.

The crystals of .Q-hydroxy-3e'chloro-5-nitroa pyridine obtainedmelt at 198?. C.- Yield 86% of the theory.

- 1.'A method'formaking 2-hydroxy compounds of pyridine which consists in treatcompoundsof the general formula in which x' is a halogen and. Y h dro en ora halogen or the hydroxy group or the nitro group, or the amino group, or the ar sonic acid group or an alkyl group or an aryl group. I

2. A method for making 2-hydroxy compounds otpyridine which consists in treating with aqueous hydrolhalic acids pyridine 1 ing with aqueous hydrolhalic acids pyridine q i compounds of the general formula V g V Y Y in which Xis chlorine and Y hydrogen or Y or the a halogen or thehydroxy. group,

nitro group, or the amino group, or the arsonic acid group or an alkyl group or an aryl group.

3. A method for making 2-hydroxy com-' pounds of pyridine which consists in treating with aqueous hydrolhalic acids pyridine compounds of the general formula in which X is a halogen and Y a halogen or the hydroxy group, or the nitro group,,or theamino group, or the arsonic acid group Oran alkyl' group or an aryIIgroup; i.

4. A method for making'Q-hydrOXy coinpounds of pyridine which consists in treat ing with-aqueous hydrolhalic acids pyridine compounds ofthegeneraliformula;

in which halogen or the ihydroxy group, or the new group, or the amino group, or the arsonic acid group, orfan alkyl group, or an aryl group.

method" for making 25hydroxy-5- v nitropyridine which consists in 'treating 2- halic acids.

' 7. A method according to claim 1 in which aqueous hydrochloric acid is used as saponifying agent.

In testimony whereof I aflix my signature.

CUBTBATH. 

